ERC FUNDED PROJECTS

"A major outstanding challenge for evolutionary biology is to explain how novel adaptations arise. We propose to test whether developmental plasticity initiates evolutionary change in morphological, behavioural and social traits, using laboratory experiments, fieldwork and comparative analyses. Using burying beetles Nicrophorus spp as our model experimental system, we shall: 1) Test whether variation in parental provisioning during development induces correlated phenotypic change in adult body size and a suite of life history traits; whether these phenotypic changes can be genetically accommodated under experimental evolution (the Baldwin Effect); and whether changes induced by experimental evolution mimic natural variation in adult body size and life history strategy among Nicrophorus species; 2) Test whether parental provisioning has a canalizing effect on the developmental environment, potentially storing up cryptic genetic variation which might then be released as random new phenotypes, if offspring are exposed to a new developmental environment; 3) Investigate whether developmental trade-offs, induced by under-provisioning from parents, provide the first step towards the evolution of a novel interspecific mutualism. Is a second species recruited in adulthood to carry out the function of a structure that was under-nourished during development? 4) Using comparative analyses of data from the literature on insects, frogs, birds and mammals, we shall test whether the evolution of parental provisioning in a given lineage is positively correlated with the number of species in the lineage. Our proposal is original in focusing on developmental plasticity induced by variation in parental provisioning. Given the diverse and numerous species that provision their young, including several whose genomes have now been sequenced, this potentially opens up a rich new area for future work on the developmental mechanisms underlying evolutionary innovations."

1 499 914 €

Start date: 2012-11-01, End date: 2017-10-31

The gastrointestinal tract is emerging as a key regulator of appetite and metabolism, but studies aimed at identifying the signals involved are faced with daunting neuroanatomical complexity: there are as many as 500 million neurons in the human gut. Drosophila should provide a simple and genetically amenable alternative, but both its autonomic nervous system and the signalling significance of its digestive tract have remained largely unexplored. My research programme will characterize the signals and neurons mediating the interaction between the nervous and digestive systems, and will establish their significance both in the maintenance of metabolic homeostasis and in response to nutritional challenges. To achieve these goals, we will capitalize on a multi-disciplinary approach that combines the genetic manipulation of defined neuronal lineages, a cell-biological approach to the study of enterocyte metabolism, and our recently developed physiological and behavioural readouts. Our work will provide new insights into the signals and mechanisms modulating internal metabolism and food intake: processes which, when deregulated, contribute to increasingly prevalent conditions such as diabetes, metabolic syndrome and obesity. Our recent finding of conserved mechanisms of autonomic control in the fruit fly makes us confident that the signals we identify will be relevant to mammalian systems.

1 499 740 €

Start date: 2013-02-01, End date: 2018-01-31

Horizontal gene transfer (HGT) is a fundamental process of bacterial evolution, accelerating adaptation to novel environments and providing access to new ecological niches. However, two of the three mechanisms of HGT, transduction and conjugation, both rely on semi-autonomous vectors (lysogenic phages and conjugative plasmids, respectively), creating the potential for coadaptation between microbe and vector. I here focus on conjugative plasmids. These encode their own replication and transfer, and as such are capable of pursuing their own fitness interests, which need not be aligned with those of their bacterial host. My thesis is that bacterial adaptation by conjugation must therefore be viewed as a co-evolutionary, rather than simply an evolutionary process as achieved to date. In this proposal I take an experimental evolution approach to derive an empirically founded understanding of bacteria-plasmid coevolutionary processes. In particular, I focus on the effects (on the pattern and process of bacteria-plasmid coevolution) of ecological variables identified in population models as crucial to the persistence of conjugative plasmids: environmental heterogeneity, spatial structure, and between-species transfer. Drawing on coevolutionary theory, I highlight that the ecological conditions expected to favour plasmid persistence may often drive the breakdown of bacteria-plasmid coadaptation. Additionally, I will determine the consequences of bacteria-plasmid coevolution for the structuring of microbial communities.

1 233 610 €

Start date: 2013-02-01, End date: 2018-01-31

Advances in genomics offer new opportunities for identifying loci that behave unusually against a background of neutral variation. Detecting divergent sites among related individuals and taxa can shed light on the process of adaptive divergence, from non-random mating to the establishment of reproductive barriers. Conversely, identifying convergent sites among unrelated taxa can offer insights into deeper level ecological radiations. This project will study genes underpinning evolutionary divergence at several stages. Discovering genome-wide ‘gene outliers’ presents enormous challenges. I argue these can be overcome by combining and applying phylogenetic and evolutionary analyses with deep sequencing to exceptional study systems. Among mammals, bats are unique in having independently evolved laryngeal echolocation and nectarivory, both implicated in their unparalleled adaptive radiation. We will (i) use a novel phylogenomic approach to identify genes under convergent and divergent selection associated with acoustic and dietary diversification. (ii) We will then discover additional loci implicated in diverging incipient sympatric taxa that have undergone recent dramatic call frequency shifts. (iii) We will identify genome-wide loci that show anomalous divergence and non-random combinations between faithfully breeding pairs of bats in a population where outbreeding increases fitness. These complementary studies will produce a database of candidate loci implicated in ecological divergence. We will then verify and synthesize our results by screening the genes in a taxonomically wider range of species. We hope to provide a comprehensive assessment of the relative numbers and importance of different types of loci in multiple stages of evolutionary divergence in a mammalian system. As such these results will significantly extend the current frontier of our knowledge about how new taxa form.

1 499 914 €

Start date: 2013-02-01, End date: 2019-01-31

INCORALS will establish a novel conceptual model that introduces a transition of symbiotic algae from a nutrient limited to a nutrient starved state as a process that renders reef building corals more susceptible to heat stress. Elevated temperatures have been identified as the key driver for coral bleaching, which is the often fatal loss of corals’ symbiotic algae. Thus, studies have estimated that reefs will be lost within the next one hundred years as a result of global warming. High temperatures undoubtedly play a major role in triggering coral bleaching. However, observations made for instance during the 1998 bleaching event, suggest also a connection between the susceptibility of corals to heat stress and anthropogenically elevated nutrient levels. Here, I present evidence that unbalanced ratios of dissolved inorganic nitrogen to phosphorus in the water column perturb the lipid composition of photosynthetic membranes of zooxanthellae and result in an increased susceptibility to thermal bleaching. I have developed a novel conceptual model of coral bleaching that introduces nutrient starvation as a cause for increased heat stress susceptibility. The model clarifies the previously unexplained correlation between the reduction of the thermal bleaching threshold of corals and their exposure to coastal run-off with elevated concentrations of dissolved inorganic nitrogen. INCORALS will conduct an in-depth study of nutrient starvation of reef corals, comparing the impact of nitrogen, phosphorus and iron. INCORALS will combine physiological experiments under tightly controlled laboratory conditions and field-based studies, using a suite of optical methods and cutting-edge molecular techniques to study this yet unexplored cause of coral bleaching and define its relevance for coral ecosystems. The improved understanding of coral bleaching gained during this project is urgently required to develop knowledge-based management strategies to support coral reef resilience.

1 285 671 €

Start date: 2012-11-01, End date: 2017-10-31

The monodromy conjecture, formulated in the seventies by the Japanese mathematician Igusa, is one of the most important open problems in the theory of singularities. It predicts a remarkable connection between certain geometric and arithmetic invariants of a polynomial f with integer coefficients. The conjecture describes in a precise way how the singularities of the complex hypersurface defined by the equation f = 0 influence the asymptotic behaviour of the number of solutions of the congruence f = 0 modulo powers of a prime. Some special cases have been solved, but the general case remains wide open. A proof of the conjecture would unveil profound relations between several branches of mathematics. In the past years, we have developed a new interpretation of the monodromy conjecture, based on non-archimedean geometry, and we have generalized it to a larger framework. A significant success of this approach was our proof of the monodromy conjecture for one-parameter degenerations of abelian varieties. The aim of our proposal is to generalize this proof to degenerations of Calabi-Yau varieties, and to adapt the arguments to the local case of the conjecture (hypersurface singularities). Degenerations of Calabi-Yau varieties play a central role in Mirror Symmetry, a mathematical theory in full development that emerged from string theory. We will explore in detail the connections between the monodromy conjecture and recent breakthroughs in Mirror Symmetry (tropical constructions of degenerating Calabi-Yau varieties). We hope to achieve these goals by combining advanced tools from several research domains, in particular: motivic integration, non-archimedean geometry, Hodge theory, logarithmic geometry and tropical geometry. We are convinced that all these research domains will greatly benefit from the systematic exploration of their mutual interactions, and that the impact of our project will go far beyond the monodromy conjecture.

1 044 980 €

Start date: 2013-05-01, End date: 2018-04-30

Understanding how species mediate ecosystem processes, such as energy and nutrient fluxes, is among the foremost challenges in ecology. Bacterial communities are pivotal for the functioning of the world’s ecosystems. Although there have been great advances in describing the biodiversity of bacteria, little effort has been directed at understanding how differences in bacterial communities translate into differences in ecosystem functioning. The proposed research will develop a comprehensive framework to determine how bacterial species affect functioning while in complex mixtures of species. Once this baseline is obtained, it is possible to ask detailed questions about the ‘functional ecology’ of bacterial communities. Foremost among these is whether ecological processes (species sorting) are more important than evolutionary processes (adaptation) in establishing species roles in ecosystems. The research has implications for the fundamental understanding how ecological communities operate.

1 484 258 €

Start date: 2013-02-01, End date: 2018-01-31

We have recently identified the molecular genetic cause of a puzzling clinical syndrome, initially termed “benign infantile mitochondrial myopathy due to reversible cytochrome c oxidase (COX) deficiency”. While childhood-onset mitochondrial encephalomyopathies are usually severe, relentlessly progressive conditions with fatal outcome, this syndrome stands out by showing complete (or almost complete) spontaneous recovery. We have detected the homoplasmic m.14674T>C mutation in the mitochondrial mt-tRNAGlu gene in 17 affected individuals from 12 independent families of different ethnic origins. The m.14674T>C mutation affects the discriminator base of mt-tRNAGlu, the last base at the 3´-end of the molecule, where the amino acid via the terminal CCA is attached, therefore thought to impair mitochondrial translation, as reflected by the COX-negative fibres and the multiple respiratory chain defects in skeletal muscle. The spontaneous recovery of the patients suggests the existence of so far unknown cellular compensatory mechanisms. We will investigate, i) why patients with reversible COX deficiency show an isolated muscle involvement, ii) why symptoms start uniformly in the first days or weeks of life, iii) what is the molecular basis of the age-dependent, spontaneous recovery, and iv) which factors influence mitochondrial protein synthesis in human cells, skeletal muscle and different tissues. We will study these factors in v) different types of mitochondrial disease. From a scientific standpoint, this is one of the few hereditary conditions with a life-threatening onset showing recovery. Finding a clearly pathogenic homoplasmic mtDNA mutation offers a new paradigm of mtDNA pathogenesis, and studying this unique disease may unveil factors that are important in other mitochondrial disease. The long-term goal would be to upregulate or boost compensatory factors in patients with mitochondrial disease with the aim to open new avenues for therapy.

1 432 075 €

Start date: 2013-03-01, End date: 2018-02-28

"The Andre-Oort conjecture is an important problem in the theory of Shimura varieties. It also has significant applications in other areas of Number Theory, such as transcendence theory. The conjecture was proved assuming the Generalised Riemann Hypothesis by Klingler, Ullmo and Yafaev. Very recently, Jonathan Pila came up with a very promising strategy for proving the Andre-Oort conjecture unconditionally. The first main aim of this proposal is to combine Pila's ideas with the ideas of Klingler-Ullmo-Yafaev in order to obtain a proof of the Andre-Oort conjecture without the assumption of the GRH. We then propose to use these methods to attack the Zilber-Pink conjecture, a very vast generalisation of Andre-Oort. We also propose to consider several problems closely related to geometry of Shimura Varieties and the Andr\'e-Oort conjecture. Namely Coleman's cponjecture on finiteness of the number of Jacobians with complex multiplication for curves of large genus, the Mumford-Tate conjecture on Galois representations attached to abelian varieties over number field and Lang's conjecture on rational points on hyperbolic varieties in the context of Shimura varieties."

697 037 €

Start date: 2012-10-01, End date: 2017-09-30